AbstractMessageConverter and messaging template implementations now
detect and use mutable headers if passed in.

The SimpMessagingTemplate is optimized to supporting using a single
MessageHeaders instance while preparing a message.

This commit also updates code using the SimpMessagingTemplate to take
advantage of its new capabilities.

Issue: SPR-11468

Mutate rather than re-create headers when decoding STOMP messages
before a message is sent on a message channel.

Use MessageBuilder.createMessage to ensure the fully prepared
MessageHeaders is used directly MessageHeaderAccessor instance.

Issue: SPR-11468

Refine semantics of ID and TIMESTAMP headers provided to protected
MessageHeaders constructor.

Refactor internal implementation of MessageHeaderAccessor.

Support mutating headers from a single thread while a message is being
built (e.g. StompDecoder creating message + then adding session id).

Improve immutablity in NativeMessageHeaderAccessor and in
StompHeaderAccessor.

Optimize object creation for initializing messages and subsequent
accessing their headers.

Introduce MessageHeaderAccessorFactory support to enable applying a
common strategies for ID and TIMESTAMP generation to every message.

Add MessageBuilder shortcut factory method for creating messages from
payload and a full-prepared MessageHeaders instance. Also add
equivalent constructors to GenericMessage and ErrorMessage.

Issue: SPR-11468

Prior to this commit it was impossible to add additional scripts to a
ResourceDatabasePopulator after setScripts() had been invoked.

This commit fixes this by ensuring that the internal scripts list
continues to be modifiable when setScripts() is invoked.

Issue: SPR-11691

Prior to this commit ResourceDatabasePopulator did not assert any
preconditions for constructor and method arguments. Consequently,
errors would not be encountered until the populator was executed.

This commit addresses this issue by ensuring that preconditions for
constructor and method arguments are asserted immediately, throwing
IllegalArgumentExceptions where appropriate.

Issue: SPR-11690

Changed the value of ScriptUtils.EOF_STATEMENT_SEPARATOR from
"<<< END OF SCRIPT >>>" to "^^^ END OF SCRIPT ^^^" so that the angle
brackets do not have to be escaped in XML configuration files.

Issue: SPR-11687

Prior to Spring Framework 4.0.3, it was possible to supply a bogus
statement separator (i.e., a separator string that does not exist in
the configured SQL scripts) to ResourceDatabasePopulator with the side
effect that the entire contents of a script file would be interpreted
as a single SQL statement.

This undocumented feature was never intentional; however, some
developers came to rely on it. Unfortunately, changes made in
conjunction with SPR-9531 and SPR-11560 caused such scenarios to no
longer work.

This commit introduces first-class support for executing scripts which
contain a single statement that spans multiple lines but is not
followed by an explicit statement separator.

Specifically, ScriptUtils.EOF_STATEMENT_SEPARATOR may now be specified
as a 'virtual' statement separator to denote that a script contains a
single statement and no actual separator.

Issue: SPR-11687

Issue: SPR-11551

Issue: SPR-11680

Issue: SPR-11600

Comes with general JDBC 3.0+ baseline upgrade, removing defensive measures.

Issue: SPR-11600

* SPR-9955:
  Introduce context bootstrap strategy in the TCF

Work done in conjunction with SPR-5243 and SPR-4588 introduced physical
package cycles in the spring-test module. The work performed in
conjunction with SPR-9924 uses reflection to resolve these physical
package cycles; however, prior to this commit the logical package
cycles still remain.

Furthermore, over time it has become apparent that the Spring
TestContext Framework (TCF) could better serve application developers
and especially third-party framework developers by providing a more
flexible mechanism for "bootstrapping" the TCF. For example, prior to
this commit, default TestExecutionListeners could only be registered by
subclassing TestContextManager (and SpringJUnit4ClassRunner if using
JUnit). Similarly, the default ContextLoader could only be set by
subclassing SpringJUnit4ClassRunner for JUnit and by copying and
modifying AbstractTestNGSpringContextTests for TestNG.

This commit addresses the aforementioned issues by introducing a
bootstrap strategy in the TestContext framework that is responsible for
determining default TestExecutionListeners and the default
ContextLoader in an extensible fashion. The new TestContextBootstrapper
SPI also provides a mechanism for supporting various types of
MergedContextConfiguration depending on the feature set of the context
loaders supported by the strategy.

The following provides an overview of the most significant changes in
this commit.

 - Introduced TestContextBootstrapper strategy SPI, BootstrapContext,
   and @BootstrapWith.

 - Introduced AbstractTestContextBootstrapper,
   DefaultTestContextBootstrapper, and WebTestContextBootstrapper
   implementations of the TestContextBootstrapper SPI and extracted
   related reflection code from ContextLoaderUtils & TestContextManager.

 - Introduced BootstrapUtils for retrieving the TestContextBootstrapper
   from @BootstrapWith, falling back to a default if @BootstrapWith is
   not present.

 - @WebAppConfiguration is now annotated with
   @BootstrapWith(WebTestContextBootstrapper.class).

 - CacheAwareContextLoaderDelegate is now an interface with a new
   DefaultCacheAwareContextLoaderDelegate implementation class.

 - Introduced closeContext(MergedContextConfiguration, HierarchyMode) in
   CacheAwareContextLoaderDelegate.

 - DefaultTestContext now uses CacheAwareContextLoaderDelegate instead
   of interacting directly with the ContextCache.

 - DefaultTestContext now delegates to a TestContextBootstrapper for
   building the MergedContextConfiguration.

 - TestContextManager now delegates to TestContextBootstrapper for
   retrieving TestExecutionListeners.

 - Deleted TestContextManager(Class, String) constructor and
   SpringJUnit4ClassRunner.getDefaultContextLoaderClassName(Class)
   method since default ContextLoader support is now implemented by
   TestContextBootstrappers.

 - Extracted ActiveProfilesUtils from ContextLoaderUtils.

 - Extracted ApplicationContextInitializerUtils from ContextLoaderUtils.

 - MetaAnnotationUtils is now a public utility class in the test.util
   package.

 - Removed restriction in @ActiveProfiles that a custom resolver cannot
   be used with the 'value' or 'profiles' attributes.

 - Introduced DefaultActiveProfilesResolver.

Issue: SPR-9955

Issue: SPR-11635
(cherry picked from commit f7a17add)

Issue: SPR-11676
(cherry picked from commit 196f629a)

Issue: SPR-11640

Issue: SPR-11637

Issue: SPR-11635

Issue: SPR-11635

Issue: SPR-11678

This commit is a general update of the Cache Abstraction chapter.

Existing sections have been updated with recent improvements made in
that area, in particular:
* Guava and JSR-107 caches support
* New @CacheConfig annotation allowing to share some key customizations
  at class-level
* CacheResolver interface used to resolve the cache(s) to use at
  runtime
* Update section on @CachePut

This commit also describes the support of standard JCache annotations,
i.e. JSR-107.

Issues: SPR-11490, SPR-11316, SPR-10629, SPR-9616, SPR-8696

This commit fixes the handling of cached exceptions in the JSR-107
advisor. Such exceptions are now properly propagated instead of being
wrapped in a RuntimeException.

Issue: SPR-9616

Issue: SPR-11640

Prior to this commit, AnnotatedJCacheableService contained an annotated
method demonstrating a failure scenario. This could break depending on
the order of the methods array as AopUtils creates the proxy if the
pointcut matches by checking each method.

On the CI server, the first method was this invalid use case so
checking if the proxy has to be created lead to an unexpected
exception. This scenario has been moved to its own private class now.

This fixes a Java6 backward compatible issue introduced in the JCache
implementation.

This commit also adds new representative tests.

Issue: SPR-9616

Prior to this commit, the CacheResolver was not used by Spring's
caching abstraction. This commit provides the necessary configuration
options to tune how a cache is resolved for a given operation.

CacheResolver can be customized globally, at the operation level or at
the class level. This breaks the CachingConfigurer class and a support
implementation is provided that implements all methods so that the
default is taken if it's not overridden. The JSR-107 support has been
updated as well, with a similar support class.

In particular, the static and runtime information of a cache
operation were mixed which prevents any forms of caching. As the
CacheResolver and the KeyGenerator can be customized, every operation
call lead to a lookup in the context for the bean.

This commit adds CacheOperationMetadata, a static holder of all
the non-runtime metadata about a cache operation. This is used
as an input source for the existing CacheOperationContext.

Caching the operation metadata in an AspectJ aspect can have side
effects as the aspect is static instance for the current ClassLoader.
The metadata cache needs to be cleared when the context shutdowns.
This is essentially a test issue only as in practice each application
runs in its class loader. Tests are now closing the context properly
to honor the DisposableBean callback.

Issue: SPR-11490

This commit adds support for the JSR-107 cache annotations alongside
the Spring's cache annotations, that is @CacheResult, @CachePut,
@CacheRemove and @CacheRemoveAll as well as related annotations
@CacheDefaults, @CacheKey and @CacheValue.

Spring's caching configuration infrastructure detects the presence of
the JSR-107 API and Spring's JCache implementation. Both
@EnableCaching and the cache namespace are able to configure the
required JCache infrastructure when necessary. Both proxy mode
and AspectJ mode are supported.

As JSR-107 permits the customization of the CacheResolver to use for
both regular and exception caches, JCacheConfigurer has been
introduced as an extension of CachingConfigurer and permits to define
those.

If an exception is cached and should be rethrown, it is cloned and
the call stack is rewritten so that it matches the calling thread each
time. If the exception cannot be cloned, the original exception is
returned.

Internally, the interceptors uses Spring's caching abstraction by default
with an adapter layer when a JSR-107 component needs to be called.
This is the case for CacheResolver and CacheKeyGenerator.

The implementation uses Spring's CacheManager abstraction behind the
scene. The standard annotations can therefore be used against any
CacheManager implementation.

Issue: SPR-9616

This commit introduces an explicit integration test to verify that a
PropertySource can be set via a custom ApplicationContextInitializer in
the Spring TestContext Framework.

Issue: SPR-11666